As is known, aluminum is obtained by electrolysis from bauxite, with the bauxite passing through several phases or process stages before alumina, and afterwards aluminum may be obtained.
At installations where this type of process is carried out, over time bauxite adheres to valve seats, and although occasionally this problem may result in the bauxite acting as a sealant between the valve disc or ring and the seat, the general results in that the disc cannot rest properly on the valve seat.
These depositions inside the valve must be removed manually.
This type of valves comprises a rod or shaft with a disc or seal solidly joined to it which is housed inside the valve body, so that these elements make up the valve itself.
The valve is driven by means of an input shaft which, through a bevel gear, drives a crown provided with recesses in which fit battlement-shaped projections provided in the spindle nut, so that the rotation of the crown is transmitted to the spindle nut, which in turn causes the valve shaft to ascend or descend, and therefore causes the coupling or decoupling of the valve disc or ring on the valve body seats.